Compressor housing and method for assembling a compressor housing

ABSTRACT

A compressor housing has a housing body that is embodied so as to be open at two opposing end faces of the housing body, and a base element which closes one of the two open end faces of the housing body in an assembled state of the compressor housing, the base element being frictionally secured in the assembled state with its outer peripheral surface against an inner peripheral surface of the housing body by means of an interference fit.

FIELD OF THE INVENTION

The invention relates to a compressor housing. The invention further relates to a method for assembling a compressor housing.

BACKGROUND OF THE INVENTION

Compressor housings for refrigerant compressors require a high burst strength, since the compressor housing should be designed for burst pressures of up to 360 bar.

A compressor housing for a refrigerant compressor is known, for example, from EP 199 15 918 A1. This has a cylinder block on which a cover, a first seal, a valve plate, and a second seal are mounted. In order to achieve the high burst strength, the cylinder block is usually formed from a cast construction, the cylinder block having a housing body on which a base element is integrally arranged. The base element is arranged on a first end face of the housing body, and the cover is arranged on a first end face opposite the second end face of the housing body. The integral design of the housing body with the base element requires an elaborate structural configuration when casting the cylinder block and thus the housing body together with the base element.

It is, therefore, the object of the invention to provide a compressor housing and a method for assembling a compressor housing in which the structural complexity and effort and expense of process engineering can be reduced despite achieving a high burst strength.

SUMMARY OF THE INVENTION

The object is achieved according to the invention by the features of the independent claims. Preferred embodiments and developments of the invention are indicated in the dependent claims.

The compressor housing according to the invention comprises a housing body that is embodied so as to be open at two opposing end faces of the housing body, and a base element which closes one of the two open end faces of the housing body in an assembled state of the compressor housing, the base element being frictionally secured in the assembled state with its outer peripheral surface against an inner peripheral surface of the housing body by means of an interference fit.

In the method according to the invention for assembling a compressor housing, a base element is introduced into a housing body having two opposing open end faces, and the base element introduced into the housing body is frictionally secured with its outer peripheral surface against an inner peripheral surface of the housing body by means of an interference fit so that, in an assembled state of the compressor housing, the base element closes one of the two end faces of the housing body.

According to the invention, a provision is now made that, in a compressor housing for a refrigerant compressor of a vehicle, the housing body and the base element are no longer integrally formed with one another, but rather the base element and the housing body are each embodied as a single piece, so that the compressor housing is put together or assembled from these two individual pieces. The housing body is embodied such that its two end faces are open. One end is closed in a sealing manner with the base element only upon assembly of the compressor housing. The other end face can be closed with a cover element after the attachment of the base element to the housing body and after the positioning of all necessary components for the refrigerant compressor in the interior of the housing body. The housing body preferably has a hollow cylindrical shape. The base element is preferably embodied as a plate element. If the housing body has a cylindrical shape, then the base element is preferably embodied as a circular plate element. In the initial state—that is, before assembly—the base element has an outer diameter that is greater than an inner diameter of the housing body. During assembly, the base element is introduced into the housing body in such a way that, in the assembled state, the base element closes an end face of the housing body in a sealing manner by means of an interference fit. A secure force fit is thus preferably formed in the assembled state between the base element and the housing body that can no longer be released after assembly. In the assembled state, the base element abuts with its outer peripheral surface against the inner peripheral surface of the housing body, with the base element being pressed with its outer peripheral surface against the inner peripheral surface of the housing body, thus enabling a high density to be achieved at the junction between the base element and the housing body. Unlike a complex structural design of an integral cast construction of housing body and base element, the attachment of the base element to the housing body by means of an interference fit can simplify the manufacture and assembly of a compressor housing.

The interference fit can be formed by shrinking the housing body onto the base element, for example. In that case, the housing body can be heated in order to form the interference fit and shrunk onto the outer peripheral surface of the base element. The housing body can be heated, particularly by thermal means, whereby the diameter of the inner peripheral surface of the housing body and thus the inner diameter of the housing body is increased. In the heated state, the inner diameter of the housing body preferably has a larger size than the outer diameter of the base element, so that the base element, which is then preferably at room temperature during assembly, can be easily inserted or placed into the housing body with play. If the base element introduced into the housing body is arranged at the desired position in the housing body, particularly in the vicinity of one of the end faces of the housing body, the housing body is cooled again to room temperature, whereby the inner diameter of the housing body is reduced again, thereby shrinking the housing body with its inner circumferential surface in a sealing manner onto the outer peripheral surface of the base element in order to form the interference fit between the base element and the housing body.

Alternatively, it is also possible for the interference fit to be formed by cold stretching of the base element. In that case, in order to form the interference fit, the base element can be cooled to a temperature below room temperature and, after the introduction of the cooled base element into the housing body, the base element, upon being heated to room temperature, is able to expand again until the base element abuts in a sealing manner with its outer peripheral surface against the inner peripheral surface housing body. As a result of the cooling of the base element to a temperature below room temperature, the material of the base element contracts, so that the outer diameter of the base element is reduced compared to its initial state and, in the process, reduced to the extent that the outer diameter of the base element is smaller than the inner diameter of the housing body, so that the base element can be introduced or placed easily and with play into the housing body, which is then preferably has room at room temperature during assembly. Once the base element introduced into the housing body has been arranged at the desired position in the housing body, particularly in the vicinity of one of the end faces of the housing body, the base element is heated again to room temperature, whereby the outer diameter of the base element is enlarged again and the base element is thereby enlarged again in its outer peripheral surface until the base element abuts in a sealing manner with its outer peripheral surface against the inner peripheral surface of the housing body, thereby forming the interference fit between the base element and the housing body.

In order to improve the tightness at the junction between the outer peripheral surface of the base element and the inner peripheral surface of the housing body, a weld can be applied at the joint between the housing body and the base element. The weld can be preferably applied over the entire region of the junction, thus forming a circular weld seam. The gas tightness of the compressor housing can be improved in particular through the additionally applied weld seam.

Preferably, the weld seam can be applied by means of a laser welding process. The laser welding process enables the weld seam to be applied in a very targeted, controlled manner, with head being inputted only very locally during welding, making it possible to prevent an undesirable heating of the parts of the housing body and the base element that are already joined by an interference fit, which might result in an undesirable displacement of the base element relative to the housing body.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional measures improving the invention are elucidated below through the description of a preferred embodiment of the invention with reference to the sole FIG. 1.

FIG. 1 shows a schematic sectional view along a longitudinal axis of a compressor housing according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The compressor housing 100 shown in FIG. 1 comprises a housing body 10, which is preferably made from a metal material. The housing body 10 is embodied in the form of a hollow cylinder. The housing body 10 is open at its two end faces 11, 12.

In addition to the housing body 10, the compressor housing 100 has a base element 13 and a cover element 14. In a assembled state as shown in FIG. 1, the base element 13 is arranged on the end face 11, and the cover element 14 is arranged on the opposing end face 12.

The cover element 14 is attached to the housing body 10 in the assembled state by means of a plurality of screws 15.

In contrast, the base element 13—which, like the cover element 14, is embodied as a separate part from the housing body 10—is frictionally secured by means of an interference fit against the housing body 10 in the assembled state due to the fact that the base element 13 abuts with its outer peripheral surface 16 in a planar and sealing manner against an inner peripheral surface 17 of the housing body 10 in an interference fit. The base element 13 abuts with its entire outer peripheral surface 16 against the inner peripheral surface 17 of the housing body 10, so that a gap-free junction 18 is formed between the base element 13 and the housing body 10.

The base element 13 is embodied as a circular plate element. It is preferably made from the same material, particularly metal material, as the housing body 10.

In the assembled state, the base element 13 is arranged in the housing body 10 in such a way that the base element 13 is flush with the end face 19 of the housing body 10 that points outward on the end face 11, as can be seen in FIG. 1.

In order to form the interference fit between the housing body 10 and the base element 13, the base element 13 has an outer diameter DA in the assembled state that is greater than the inner diameter Di of the housing body 10. In the assembled state, the outer diameter DA of the base element 13 is equal to the inner diameter Di of the housing body 10.

The interference fit for the frictional joining of the housing body 10 to the base element 13 can be formed by shrinking the housing body 10 onto the base element 13. In this case, the housing body 10 is thermally heated, so that the housing body 10 expands and the inner diameter Di of the housing body 10 is thus enlarged. On the other hand, the base element 13 is not heated, but is at a temperature approximately equal to room temperature. As a result of the enlargement of the inner diameter D_(I) of the housing body 10, it becomes larger than the outer diameter DA of the base element 13. In the heated state of the housing body 10, the base element 13 is introduced into the housing body 10 by positioning the base element 13 on the inner peripheral surface 17 in the vicinity of the end face 11 of the housing body 10. Upon renewed cooling of the housing body 10, the material of the housing body 10 contracts again, so that the inner diameter D_(I) of the housing body 10 decreases again and the housing body 10 thus shrinks with its inner peripheral surface 17 onto the outer peripheral surface 16 of the base element 13. Due to the shrinking, an interference fit is formed between the base element 13 and the housing body 10, enabling a sealed attachment of the base element 13 to the housing body 10 to be achieved.

Alternatively, it is also possible for the interference fit to be formed through cold stretching of the base element 13. In that case, the base element 13 is cooled to a temperature below room temperature, as a result of which the material of the base element 13 contracts and the outer diameter D_(A) of the base element 13 is thus reduced. In the cooled state of the base element 13, the base element 13 has an outer diameter D_(A) that is smaller than the inner diameter D_(I) of the housing body 10. In this cooled state, the base element 13 is introduced into the housing body 10 and positioned at the end face 11 to be closed. Once the base element 13 warms up again to room temperature, the outer diameter D_(A) of the base element 13 increases again, whereby the base element 13 again increases in its outer peripheral surface 16 until the base element 13 abuts in a sealing manner with its outer peripheral surface 16 against the inner peripheral surface 17 of the housing body 10, thus forming a force fit or an interference fit between the base element 13 and the housing body 10.

In order to seal the junction 18 between the outer peripheral surface 16 of the base element 13 and the inner peripheral surface 17 of the housing body 10 even better, particularly in a gas-tight manner, a weld seam 20 is applied to the junction 18 from outside the compressor housing 100. The weld seam 20 preferably extends over the entire length of the junction 18. However, the weld seam 20 can also be applied to the junction 18 at points along the length of the junction 18.

The weld seam 20 can be applied to the junction 18 by means of a laser welding process.

The invention is not limited in its execution to the abovementioned preferred embodiment. Rather, a number of variants are conceivable that make use of the illustrated solution even in the form of fundamentally different embodiments. All of the features and/or advantages that follow from the claims of the description or the drawings, including structural details of spatial arrangements and method steps, can be essential to the invention, both individually and in the most diverse combinations.

LIST OF REFERENCE SYMBOLS

100 compressor housing

10 housing body

11 end face

12 end face

13 base element

14 cover element

15 screw

16 outer peripheral surface

17 inner peripheral surface

18 junction

19 end face

20 weld seam

D_(A) outer diameter of the base element

D_(I) inner diameter of the housing body 

1. A compressor housing comprising: a housing body that is embodied so as to be open at two opposing end faces of the housing body, and a base element that closes one of the two open end faces of the housing body in an assembled state of the compressor housing, wherein, in the assembled state, the base element is frictionally secured by means of an interference fit with its outer peripheral surface against an inner peripheral surface of the housing body.
 2. The compressor housing as set forth in claim 1, wherein the interference fit is formed by shrinking the housing body onto the base element.
 3. The compressor housing as set forth in claim 1, wherein the interference fit is formed through cold stretching of the base element.
 4. The compressor housing as set forth in claim 1, further comprising a weld seam applied at a junction between the housing body and the base element.
 5. The compressor housing as set forth in claim 4, wherein the weld seam is applied by means of a laser welding process.
 6. A method for assembling a compressor housing, comprising: Introducing a base element into a housing body having two opposing open end faces, and frictionally securing the base element into the housing body with an outer peripheral surface of the base element against an inner peripheral surface of the housing body by means of an interference fit so that, in an assembled state of the compressor housing, the base element closes one of the two end faces of the housing body.
 7. The method as set forth in claim 6, further comprising forming the interference fit by heating and shrinking the housing body onto the outer peripheral surface of the base element.
 8. The method as set forth in claim 6, further comprising forming the interference fit by cooling the base element to a temperature below room temperature and, after the introduction of the cooled base element into the housing body, allowing the base element to expand during heating to room temperature until the base element abuts with its outer peripheral surface against the inner peripheral surface of the housing body.
 9. The method as set forth in claim 6, further comprising applying a weld seam at a junction between the housing body and the base element.
 10. The method as set forth in claim 9, wherein applying the weld seam is by means of a laser welding process. 